EVALUATION OF ANTICANCER POTENTIAL OF EIGHT VEGETAL SPECIES FROM THE STATE OF OAXACA.

Background: Eight plant species from Oaxaca, some of them used in traditional medicine, were subjected to screening of several biological activities to provide data regarding their anticancer potential, although no scientific information is available about their pharmacological effects.

Materials and methods: Methanol extracts from stems or roots of the eight plants were tested for antioxidant activity by the DPPH- method. Antimicrobial activity was determined using the agar diffusion method and the minimal inhibitory concentration (MIC) was obtained by broth dilution method. Antitopoisomerase activity was assessed using mutant strains of Saccharomyces cerevisiae JN362a, JN394, JN394t_-1, JN394t₂.₄ and JN394t_2-5. The mutagenic activity was evaluated using the Ames test (Salmonella typhimurium TA1535).

Results: No extract showed significant antioxidant activity. The best antimicrobial activity was observed for Salpianthus arenarius (MIC 56.25 μg/mL) and Lantana achyranthifolia (MIC 78.12 μg/mL) against Staphylococcus aureus. Extracts of Acalypha cuspidata, Alloispermum integrifolium and L. achyranthifolia stems showed antitopoisomerase II activity with JN394_t-1 growth of -30.88±0.0%, -38.11±4.95%, and -70.97±12.02% respectively. Galium mexicanum stem extract showed antitopoisomerase I activity with growth of 35.31±6.36% on the same mutant strain. All plant extracts were non-mutagenic. Fractionation of A. cuspidata extract led to identification of two subfractions with antitopoisomerase I and II activity at 154μg/mL (Positive controls 50 and 100μg/mL).

Conclusion: Methanol extracts of A. cuspidata, A. integrifolium, G. mexicanum, and L. achyranthifolia stems showed antitopoisomerase and non-mutagenic activities, and consequently could be promising as a source of anticancer drugs.